EP3562727B1 - Method for supplying air at a controlled temperature to a cabin of a land vehicle, and land vehicle - Google Patents

Description

The invention relates to a method of supplying air at controlled temperature to a cabin of a land vehicle - in particular a railway vehicle - in which at least one air cycle device is used. It extends to a land vehicle - in particular a rail vehicle - comprising at least one air cycle device.

• « véhicule terrestre » désigne tout véhicule de transport à la surface de la terre dans l'atmosphère, et englobe en particulier les véhicules roulant (véhicules ferroviaires roulant sur rails et véhicules routiers), et les navires (véhicules se déplaçant sur l'eau) ; à l'exclusion en particulier des engins volants tels que les aéronefs, les engins spatiaux et les sous-marins pour lesquels les problèmes techniques qui se posent sont très différents, notamment en raison des besoins spécifiques de pressurisation de la cabine,
• « cabine » désigne tout espace clos d'un véhicule dans lequel la température de l'air doit être contrôlée, et englobe en particulier les cabines pour passagers, les postes de pilotage et les soutes à bagages ou à transport de fret à température contrôlée,
• « conditionnement d'air » désigne le fait de contrôler au moins la température de l'air dans une cabine en le refroidissant ou en le réchauffant ; le conditionnement d'air dans une cabine peut également éventuellement permettre de contrôler au moins un autre paramètre de l'air dans la cabine, notamment choisi parmi l'humidité, la pression, un débit d'air entrant dans la cabine, un débit d'air sortant de la cabine.

Throughout the text, the following terminology is adopted:

• "Land vehicle" means any transport vehicle on the earth's surface in the atmosphere, and includes in particular rolling vehicles (rail vehicles running on rails and road vehicles), and ships (vehicles moving on water) ; with the exception in particular of flying vehicles such as aircraft, spacecraft and submarines for which the technical problems which arise are very different, in particular because of the specific needs of cabin pressurization,
• "Cabin" means any enclosed space of a vehicle in which the air temperature must be controlled, and includes in particular passenger cabins, cockpits and baggage or cargo compartments at controlled temperature,
• "Air conditioning" means controlling at least the temperature of the air in a cabin by cooling or heating it; air conditioning in a cabin can also optionally make it possible to control at least one other parameter of the air in the cabin, in particular chosen from humidity, pressure, an air flow rate entering the cabin, a flow rate of air coming out of the cabin.

Most environmental control systems (often designated by the acronym ECS) allowing air conditioning on board land vehicles include at least one two-phase cycle device (often denoted by the acronym VCS), that is to say comprising a fluid two-phase liquid / vapor coolant driven in a closed thermal loop comprising at least one compressor and one evaporator, the vaporization of the heat transfer fluid causing the production of cold power allowing the air to be cooled in the cabin. With those systems, heating is usually done by electric heaters. It is rarely possible to envisage reheating by inversion of the heat pump cycle, given the fact that the ranges of environmental conditions in which the operation of the heat pump cycle is possible are relatively restricted and insufficient in the context operating on board a land vehicle likely to encounter various environmental conditions.

These two-phase cycle systems have the drawback of requiring heat transfer fluids which are halocarbon (chlorofluorocarbons (CFC), hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFC)) or hydrofluorolefins (HFO) which, due to their harmfulness to the environment and / or their dangerousness for humans (destruction of the ozone layer, strong global warming potential, imperatives of recovery by authorized structures, toxicity, risk of ignition, etc.), are bound to disappear. In addition, it turns out that these two-phase cycles are poorly adapted to high outside temperatures, and can be interrupted in environmental conditions in which the air conditioning needs are precisely the most important. This results in considerable inconvenience for passengers, and even risks in terms of security or conservation of goods.

Accordingly, there is a need to provide a temperature controlled air supply method and device for a land vehicle cabin based on a single phase air cycle, i.e. by using only air. gaseous air as heat transfer fluid.

Two types of solution have been proposed for this purpose.

In a first type of known solution ( EP 0581237 ), a direct loop air cycle device has been proposed in which the fresh air is compressed by a first electric compressor, then passes through a heat exchanger for its intermediate cooling before a second compressor driven by a turbine. On leaving the second compressor, the air passes through exchangers which allow it to be cooled by the outside air, then through a water condenser before being fed to the turbine. The air relaxed by the turbine passes through an antifreeze mixing chamber, then through a first condenser to cool the air upstream of the turbine in which the water is to be condensed, then through a second condenser to be fed into a mixing chamber where it can be mixed with recirculating air and / or fresh air before being supplied to the cabin via a filter. It turns out that this first type of solution is however not sufficiently reliable or robust in use. In fact, the electric compressors necessary for the first compression stage are delicate components which wear out quickly due to the numerous stops and starts to which they are subject during operation. In addition, this solution requires a plurality of rotating machines (first stage of electric compressor, turbocharger, four groups of electric fans) cumbersome, heavy, expensive to install and maintain, and requiring relatively complex control logic.

In a second known type of solution ( EP 1177961 , EP 1186501 ) it has been proposed a reverse-loop air cycle device in which a flow of air at atmospheric pressure is supplied to the inlet of a turbine to be expanded and cooled, then passed through an air / air exchanger in in which the exchange of frigories is done with forced air inside the cabin of the vehicle by means of electric fans. The expanded air is then drawn in by a compressor in which it is recompressed to atmospheric pressure to be discharged outside.

This second type of solution is generally satisfactory in terms of reliability and performance, and has been used for more than 10 years on board trains, especially in Germany. However, it has the drawback of a relatively large size, in particular in height. Indeed, the air flow in the cycle of the turbocharger taking place at a pressure lower than atmospheric pressure (typically of the order of 0.5 10 ⁵ Pa) requires the use of bulky components: pipes with large sections , large diameter volutes, relatively low turbocharger rotational speed. However, this height requirement can prove to be particularly penalizing, in particular for rail vehicles in which groups of air conditioning systems are generally placed on the roof, and the total height of which is limited on the one hand for passage under bridges or in tunnels and on the other hand to promote the aerodynamics of the vehicle. This is the case in particular for high speed trains.

In addition, in these two types of solution, an electric heater, whose coefficient of performance is not greater than 1, must be placed downstream of the air / air exchanger for heating the air in the cabin.

FROM 102004063840 also describes a method and an air conditioning device that can be switched between a cooling mode and a heating mode, but the energy performance of which is not optimized.

The document GB 2 237 373 A also describes an air conditioning method and device.

The invention therefore aims to overcome all of these drawbacks.

It aims in particular to propose a method of supplying air at controlled temperature with an air cycle for the cabin of a land vehicle having a reduced overall height - in particular compatible with its installation on the roof of railway vehicles -, and which is reliable and robust. , light, simple, inexpensive to install and maintain, and effective in all environmental conditions that may potentially be encountered.

It also aims to propose such a method resulting in lower energy consumption of the vehicle, and in particular in which the heating of the cabin can be carried out with a coefficient of performance greater than 1.

It also aims to propose such a method making it possible, from the same air cycle device, to easily modulate the production capacity in cold or hot thermal power according to the needs of the application, and to ensure redundancy. partial air conditioning function in case of partial failure. Thus, it aims to provide a process that is easily adaptable to a large number of different land vehicles, having air conditioning needs that can vary over a wide range, without require the design and manufacture of air conditioning units and turbomachines specific to each application.

The invention also aims to provide a land vehicle having the same advantages.

• au moins un turbocompresseur comprenant :
  • ∘ un compresseur rotatif,
  • ∘ une turbine rotative,
  • ∘ un arbre couplant la turbine et le compresseur de telle sorte que la turbine est apte à entraîner le compresseur en rotation,
  • ∘ une entrée d'air du compresseur,
  • ∘ une sortie d'air du compresseur délivrant un débit d'air comprimé par le compresseur,
  • ∘ une entrée d'air de la turbine agencée pour recevoir un débit d'air comprimé en provenance du compresseur,
  • ∘ une sortie d'air de la turbine délivrant un débit d'air froid détendu,
• au moins un échangeur interposé entre la sortie d'air du compresseur et l'entrée d'air de la turbine,

caractérisé en ce que :

• on utilise au moins un turbocompresseur d'au moins un dispositif à cycle à air -notamment chaque turbocompresseur d'au moins un dispositif à cycle à air, plus particulièrement chaque turbocompresseur de chaque dispositif à cycle à air- comportant un moteur électrique couplé au compresseur -notamment interposé sur un arbre entre la turbine et le compresseur- de façon à pouvoir délivrer une puissance mécanique au compresseur,
• l'entrée d'air du compresseur est agencée pour recevoir de l'air à pression supérieure ou égale à la pression atmosphérique.

The invention therefore relates to a method for supplying air at controlled temperature to a cabin of a land vehicle - in particular a rail vehicle - in which at least one air cycle device is used, comprising:

• at least one turbocharger comprising:
  • ∘ a rotary compressor,
  • ∘ a rotary turbine,
  • ∘ a shaft coupling the turbine and the compressor so that the turbine is able to drive the compressor in rotation,
  • ∘ an air inlet for the compressor,
  • ∘ an air outlet from the compressor delivering a flow of compressed air by the compressor,
  • ∘ an air inlet of the turbine designed to receive a flow of compressed air from the compressor,
  • ∘ an air outlet from the turbine delivering a flow of expanded cold air,
• at least one exchanger interposed between the air outlet of the compressor and the air inlet of the turbine,

characterized in that:

• at least one turbocharger of at least one air cycle device is used - in particular each turbocharger of at least one air cycle device, more particularly each turbocharger of each air cycle device - comprising an electric motor coupled to the compressor - in particular interposed on a shaft between the turbine and the compressor - so as to be able to deliver mechanical power to the compressor,
• the air inlet of the compressor is arranged to receive air at a pressure greater than or equal to atmospheric pressure.

• la turbine de chaque turbocompresseur est agencée pour délivrer un débit d'air détendu à pression supérieure ou égale à la pression atmosphérique,
• chaque turbocompresseur de chaque dispositif à cycle à air est associé à un ensemble de conduites et de vannes commandées, adapté pour pouvoir être commandé selon un mode de fonctionnement choisi au moins parmi :
  • ▪ un mode de chauffage dans lequel l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur traverse au moins un premier circuit (« passe chaude ») d'un échangeur de chaleur adapté pour réchauffer un débit d'air d'alimentation de la cabine du véhicule,
  • ▪ un mode de refroidissement dans lequel :
    • ∘ l'entrée d'air du compresseur est agencée pour recevoir de l'air extérieur au véhicule,
    • ∘ la sortie d'air comprimé du compresseur est reliée à au moins un échangeur de chaleur, dit échangeur intermédiaire, délivrant un flux d'air comprimé refroidi par au moins un flux d'air choisi parmi un flux d'air extérieur, un flux d'air vicié à évacuer hors de la cabine, et leurs mélanges,
• l'entrée d'air du compresseur est agencée pour, en mode de refroidissement, recevoir directement de l'air prélevé à l'extérieur du véhicule,
• en mode de refroidissement, le débit d'air froid détendu délivré par la sortie d'air de la turbine est introduit dans la cabine du véhicule, avec mélange avec de l'air de recirculation en provenance de la cabine, et éventuellement avec de l'air frais,
• en mode de chauffage, ledit débit d'air d'alimentation de la cabine du véhicule est formé par au moins un flux d'air choisi parmi un flux d'air extérieur, un flux d'air de recirculation en provenance de la cabine du véhicule, et leurs mélanges, ce flux d'air traversant le deuxième circuit de l'échangeur de chauffage cabine pour être réchauffé,
• dans une première variante en mode de chauffage par pompe à chaleur :
  • ∘ l'entrée d'air du compresseur est agencée pour recevoir un débit d'air détendu en provenance de la turbine par l'intermédiaire d'au moins un échangeur de chaleur, dit échangeur intermédiaire de réchauffage, adapté pour réchauffer l'air détendu délivré par la turbine au contact d'au moins un flux d'air - notamment au contact d'un flux d'air- choisi parmi un flux d'air extérieur, un flux d'air vicié à évacuer hors de la cabine, et leurs mélanges,
  • ∘ l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur traverse un premier circuit (« passe chaude ») d'un échangeur de chaleur, dit échangeur de chauffage cabine, adapté pour réchauffer un débit d'air d'alimentation de la cabine du véhicule traversant un deuxième circuit (« passe froide ») de l'échangeur de chauffage cabine, une sortie du premier circuit de l'échangeur de chauffage cabine étant reliée à l'entrée d'air de la turbine,
• dans une deuxième variante en mode de chauffage :
  ∘ ledit ensemble de conduites et de vannes commandées est adapté pour pouvoir être commandé également selon un mode de fonctionnement choisi parmi un mode de chauffage dans lequel :
  • ∘ un flux d'air vicié à évacuer de la cabine est alimenté à l'entrée du compresseur du turbocompresseur,
  • ∘ l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur, traverse au moins un échangeur interposé entre la sortie d'air du compresseur d'au moins un turbocompresseur et l'entrée d'air de la turbine du turbocompresseur,
  • ∘ et l'air délivré à la sortie de la turbine du turbocompresseur est relié à une bouche de sortie pour être rejeté à l'extérieur,
• la vitesse de rotation du moteur électrique de chaque turbocompresseur est pilotée en fonction d'une puissance thermique de consigne à délivrer à la cabine du véhicule,
• en mode de refroidissement, la vitesse de rotation du moteur électrique de chaque turbocompresseur est pilotée en fonction d'une puissance froide de consigne à la sortie de la turbine,
• en mode de chauffage, la vitesse de rotation du moteur électrique de chaque turbocompresseur est pilotée en fonction d'une puissance chaude de consigne à la sortie du compresseur,
• la vitesse de rotation du moteur électrique de chaque turbocompresseur est pilotée avec une valeur maximum supérieure à 50000 tr/min, notamment avec une valeur maximum comprise entre 50000 tr/min et 100000 tr/min, par exemple de l'ordre de 65000 tr/min,
• l'humidité de l'air comprimé délivré à l'entrée d'air de la turbine est extraite à l'amont de cette entrée d'air ; cette extraction peut être réalisée par une boucle d'extraction d'humidité comprenant successivement un premier circuit (« passe chaude ») d'un échangeur de chaleur réchauffeur recevant le débit d'air comprimé et refroidi à la sortie de l'échangeur intermédiaire de refroidissement, un premier circuit (« passe chaude ») d'un échangeur de chaleur condenseur, un dispositif d'extraction d'eau liquide, un deuxième circuit (« passe froide ») de l'échangeur de chaleur réchauffeur recevant le débit d'air délivré à l'aval du dispositif d'extraction d'eau liquide pour le réchauffer par le débit d'air comprimé alimentant le premier circuit de l'échangeur de chaleur réchauffeur, un deuxième circuit (« passe froide ») de l'échangeur de chaleur condenseur recevant le débit d'air froid détendu délivré par la sortie d'air de la turbine pour refroidir le débit d'air comprimé traversant le premier circuit de l'échangeur de chaleur condenseur de façon à condenser l'humidité présente dans ce débit d'air comprimé,
• on choisit chaque turbocompresseur de telle sorte qu'il présente un diamètre maximum (volute) inférieur à 400 mm, par exemple compris entre 300 mm et 400 mm, notamment de l'ordre de 360 mm,
• on choisit chaque turbocompresseur de telle sorte qu'il présente un poids inférieur à 50 kg, par exemple compris entre 20 kg et 50 kg, notamment de l'ordre de 30 kg.

In certain advantageous embodiments, a method according to the invention is also characterized by all or part of the characteristics mentioned below:

• the turbine of each turbocharger is designed to deliver a flow of expanded air at a pressure greater than or equal to atmospheric pressure,
• each turbocharger of each air cycle device is associated with a set of conduits and controlled valves, adapted to be able to be controlled according to an operating mode chosen at least from:
  • ▪ a heating mode in which the compressed and heated air delivered to the outlet of the compressor of the turbocharger passes through at least a first circuit (“hot pass”) of a heat exchanger suitable for heating a feed air flow from the vehicle cabin,
  • ▪ a cooling method in which:
    • ∘ the air inlet of the compressor is designed to receive air outside the vehicle,
    • ∘ the compressed air outlet of the compressor is connected to at least one heat exchanger, called an intermediate exchanger, delivering a flow of compressed air cooled by at least one flow of air chosen from an outside air flow, a flow of stale air to be evacuated from the cabin, and their mixtures,
• the air inlet of the compressor is arranged to, in cooling mode, directly receive the air taken from outside the vehicle,
• in cooling mode, the flow of expanded cold air delivered by the air outlet of the turbine is introduced into the cabin of the vehicle, with mixing with the recirculating air coming from the cabin, and possibly with 'fresh air,
• in heating mode, said air flow for supplying the vehicle cabin is formed by at least one air flow chosen from an outside air flow, a recirculating air flow coming from the cabin of the vehicle. vehicle, and their mixtures, this air flow passing through the second circuit of the cabin heating exchanger to be heated,
• in a first variant in heat pump heating mode:
  • ∘ the air inlet of the compressor is designed to receive a flow of expanded air from the turbine via at least one heat exchanger, called an intermediate reheating exchanger, suitable for reheating the expanded air delivered by the turbine in contact with at least one air flow - in particular in contact with an air flow - chosen from an outside air flow, a stale air flow to be evacuated out of the cabin, and their mixtures,
  • ∘ the compressed and heated air delivered to the outlet of the turbocharger compressor passes through a first circuit ("hot pass") of a heat exchanger, called the cabin heating exchanger, adapted to heat a supply air flow of the cabin of the vehicle passing through a second circuit (“cold pass”) of the cabin heating exchanger, an outlet of the first circuit of the cabin heating exchanger being connected to the air inlet of the turbine,
• in a second variant in heating mode:
  ∘ said set of conduits and controlled valves is adapted to be able to be controlled also according to an operating mode chosen from a heating mode in which:
  • ∘ a flow of stale air to be evacuated from the cabin is supplied to the inlet of the turbocharger compressor,
  • ∘ the compressed and heated air delivered at the outlet of the compressor of the turbocharger, passes through at least one exchanger interposed between the air outlet of the compressor of at least one turbocharger and the air inlet of the turbine of the turbocharger,
  • ∘ and the air delivered to the outlet of the turbocharger turbine is connected to an outlet to be discharged to the outside,
• the speed of rotation of the electric motor of each turbocharger is controlled as a function of a set thermal power to be delivered to the cabin of the vehicle,
• in cooling mode, the speed of rotation of the electric motor of each turbocharger is controlled as a function of a set cold power at the outlet of the turbine,
• in heating mode, the speed of rotation of the electric motor of each turbocharger is controlled as a function of a setpoint hot power at the compressor outlet,
• the speed of rotation of the electric motor of each turbocharger is controlled with a maximum value greater than 50,000 rev / min, in particular with a maximum value between 50,000 rev / min and 100,000 rev / min, for example of the order of 65,000 rev / min,
• the humidity of the compressed air delivered to the air inlet of the turbine is extracted upstream of this air inlet; this extraction can be carried out by a moisture extraction loop comprising successively a first circuit ("hot pass") of a reheating heat exchanger receiving the flow of compressed and cooled air at the outlet of the intermediate heat exchanger. cooling, a first circuit ("hot pass") of a condenser heat exchanger, a device for extracting liquid water, a second circuit ("cold pass") of the reheater heat exchanger receiving the flow of air delivered downstream of the liquid water extraction device to heat it by the flow of compressed air supplying the first circuit of the reheater heat exchanger, a second circuit ("cold pass") of the exchanger condenser heat receiving the flow of expanded cold air delivered by the air outlet of the turbine to cool the flow of compressed air passing through the first circuit of the condenser heat exchanger so as to condense the moisture present in this air flow c omitted,
• each turbocharger is chosen such that it has a maximum diameter (volute) less than 400 mm, for example between 300 mm and 400 mm, in particular of the order of 360 mm,
• each turbocharger is chosen such that it has a weight of less than 50 kg, for example between 20 kg and 50 kg, in particular of the order of 30 kg.

• au moins un turbocompresseur comprenant :
  • ∘ un compresseur rotatif,
  • ∘ une turbine rotative,
  • ∘ un arbre couplant la turbine et le compresseur de telle sorte que la turbine est apte à entraîner le compresseur en rotation,
  • ∘ une entrée d'air du compresseur,
  • ∘ une sortie d'air du compresseur délivrant un débit d'air comprimé par le compresseur,
  • ∘ une entrée d'air de la turbine agencée pour recevoir un débit d'air comprimé en provenance du compresseur,
  • ∘ une sortie d'air de la turbine délivrant un débit d'air froid détendu,
• au moins un échangeur interposé entre la sortie d'air du compresseur d'au moins un turbocompresseur et l'entrée d'air de la turbine d'au moins un turbocompresseur,

caractérisé en ce que :

• au moins un turbocompresseur d'au moins un dispositif à cycle à air -notamment chaque turbocompresseur d'au moins un dispositif à cycle à air, plus particulièrement chaque turbocompresseur de chaque dispositif à cycle à air-comporte un moteur électrique couplé au compresseur -notamment interposé sur un arbre entre la turbine et le compresseur- de façon à pouvoir délivrer une puissance mécanique au compresseur,
• l'entrée d'air du compresseur d'au moins un turbocompresseur d'au moins un dispositif à cycle à air -notamment de chaque turbocompresseur d'au moins un dispositif à cycle à air, plus particulièrement de chaque turbocompresseur de chaque dispositif à cycle à air- est agencée pour recevoir de l'air à pression supérieure ou égale à la pression atmosphérique.

The invention also extends to a land vehicle - in particular a rail vehicle - comprising at least one air cycle device comprising:

• at least one turbocharger comprising:
  • ∘ a rotary compressor,
  • ∘ a rotary turbine,
  • ∘ a shaft coupling the turbine and the compressor so that the turbine is able to drive the compressor in rotation,
  • ∘ an air inlet for the compressor,
  • ∘ an air outlet from the compressor delivering a flow of compressed air by the compressor,
  • ∘ an air inlet of the turbine designed to receive a flow of compressed air from the compressor,
  • ∘ an air outlet from the turbine delivering a flow of expanded cold air,
• at least one exchanger interposed between the air outlet of the compressor of at least one turbocharger and the air inlet of the turbine of at least one turbocharger,

characterized in that:

• at least one turbocharger of at least one air cycle device - in particular each turbocharger of at least one air cycle device, more particularly each turbocharger of each air cycle device - comprises an electric motor coupled to the compressor - in particular interposed on a shaft between the turbine and the compressor - so as to be able to deliver mechanical power to the compressor,
• the air inlet of the compressor of at least one turbocharger of at least one air cycle device - in particular of each turbocharger of at least one air cycle device, more particularly of each turbocharger of each cycle device air- is arranged to receive air at a pressure greater than or equal to atmospheric pressure.

• la turbine de chaque turbocompresseur est agencée pour délivrer un débit d'air détendu à pression supérieure ou égale à la pression atmosphérique,
• chaque dispositif à cycle à air comporte un ensemble de vannes commandées et de conduites et le véhicule comporte au moins une unité de régulation adaptée pour pouvoir commander chaque dispositif à cycle à air selon un mode de fonctionnement choisi au moins parmi :
  • ▪ un mode de chauffage dans lequel l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur traverse au moins un premier circuit (« passe chaude ») d'un échangeur de chaleur adapté pour réchauffer un débit d'air d'alimentation de la cabine du véhicule,
  • ▪ un mode de refroidissement dans lequel :
    • ∘ l'entrée d'air du compresseur est agencée pour recevoir de l'air extérieur au véhicule,
    • ∘ la sortie d'air comprimé du compresseur est reliée à au moins un échangeur de chaleur, dit échangeur intermédiaire de refroidissement, délivrant un flux d'air comprimé refroidi par au moins un flux d'air choisi parmi un flux d'air extérieur, un flux d'air vicié à évacuer hors de la cabine, et leurs mélanges,
• l'entrée d'air du compresseur est agencée pour, en mode de refroidissement, recevoir directement de l'air prélevé à l'extérieur du véhicule,
• dans une première variante en mode de chauffage par pompe à chaleur :
  • ∘ l'entrée d'air du compresseur est agencée pour recevoir un débit d'air détendu en provenance de la turbine par l'intermédiaire d'au moins un échangeur de chaleur, dit échangeur intermédiaire de réchauffage, adapté pour réchauffer l'air détendu délivré par la turbine au contact d'un flux d'air choisi parmi un flux d'air extérieur, un flux d'air vicié à évacuer hors de la cabine, et leurs mélanges,
  • ∘ l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur traverse un premier circuit (« passe chaude ») d'un échangeur de chaleur, dit échangeur de chauffage cabine, adapté pour réchauffer un débit d'air d'alimentation de la cabine du véhicule traversant un deuxième circuit (« passe froide ») de l'échangeur de chauffage cabine, une sortie du premier circuit de l'échangeur de chauffage cabine étant reliée à l'entrée d'air de la turbine,
• ledit échangeur intermédiaire de refroidissement et ledit au moins un échangeur intermédiaire de réchauffage sont formés d'un seul et même échangeur de chaleur,
• dans une deuxième variante en mode de chauffage :
  ∘ ledit ensemble de conduites et de vannes commandées est adapté pour pouvoir être commandé également selon un mode de fonctionnement choisi parmi un mode de chauffage dans lequel :
  • ∘ un flux d'air vicié à évacuer de la cabine est alimenté à l'entrée du compresseur du turbocompresseur,
  • ∘ l'air comprimé et réchauffé délivré à la sortie du compresseur du turbocompresseur, traverse au moins un échangeur interposé entre la sortie d'air du compresseur d'au moins un turbocompresseur et l'entrée d'air de la turbine du turbocompresseur,
  • ∘ et l'air délivré à la sortie de la turbine du turbocompresseur est relié à une bouche de sortie pour être rejeté à l'extérieur,
• il comporte une unité de régulation adaptée pour piloter la vitesse de rotation du moteur électrique de chaque turbocompresseur en fonction d'une puissance thermique de consigne à délivrer à la cabine du véhicule,
• au moins un -notamment chaque- turbocompresseur présente un diamètre maximum (volute) inférieur à 400 mm, par exemple compris entre 300 mm et 400 mm, notamment de l'ordre de 360 mm,
• au moins un -notamment chaque- turbocompresseur présente un poids inférieur à 50 kg, par exemple compris entre 20 kg et 50 kg, notamment de l'ordre de 30 kg,
• au moins un -notamment chaque- turbocompresseur est adapté pour pouvoir être piloté avec une vitesse de rotation maximum supérieure à 50000 tr/min, notamment comprise entre 50000 tr/min et 100000 tr/min, par exemple de l'ordre de 65000 tr/min,
• au moins un -notamment chaque- dispositif à cycle à air comporte un dispositif d'extraction, à l'amont de l'entrée d'air de la turbine, de l'humidité de l'air comprimé délivré, en mode de refroidissement, à la sortie d'air comprimé du compresseur ; dans certains modes de réalisation, ce dispositif extraction comprend une boucle d'extraction d'humidité comprenant successivement un premier circuit (« passe chaude ») d'un échangeur de chaleur réchauffeur relié à l'échangeur intermédiaire de refroidissement pour pouvoir recevoir le débit d'air comprimé (et refroidi) délivré par cet échangeur intermédiaire de refroidissement, un premier circuit (« passe chaude ») d'un échangeur de chaleur condenseur, un dispositif d'extraction d'eau liquide, un deuxième circuit (« passe froide ») de l'échangeur de chaleur réchauffeur reliée au dispositif d'extraction d'eau liquide pour pouvoir recevoir le débit d'air délivré à l'aval du dispositif d'extraction d'eau liquide pour le réchauffer par le débit d'air comprimé alimentant le premier circuit de l'échangeur de chaleur réchauffeur, un deuxième circuit (« passe froide ») de l'échangeur de chaleur condenseur reliée à la sortie de la turbine pour pouvoir recevoir le débit d'air froid détendu délivré par la sortie d'air de la turbine, et refroidir le débit d'air comprimé traversant le premier circuit de l'échangeur de chaleur condenseur de façon à condenser l'humidité présente dans ce débit d'air comprimé.

In certain advantageous embodiments, a vehicle according to the invention is also characterized by all or some of the characteristics mentioned below:

• the turbine of each turbocharger is designed to deliver a flow of expanded air at a pressure greater than or equal to atmospheric pressure,
• each air cycle device comprises a set of controlled valves and pipes and the vehicle comprises at least one regulation unit adapted to be able to control each air cycle device according to an operating mode chosen at least from:
  • ▪ a heating mode in which the compressed and heated air delivered to the outlet of the compressor of the turbocharger passes through at least a first circuit (“hot pass”) of a heat exchanger suitable for heating a feed air flow from the vehicle cabin,
  • ▪ a cooling method in which:
    • ∘ the air inlet of the compressor is designed to receive air outside the vehicle,
    • ∘ the compressed air outlet of the compressor is connected to at least one heat exchanger, called an intermediate cooling exchanger, delivering a flow of compressed air cooled by at least one flow of air chosen from an outside air flow, a stale air flow to be evacuated from the cabin, and their mixtures,
• the air inlet of the compressor is arranged to, in cooling mode, directly receive the air taken from outside the vehicle,
• in a first variant in heat pump heating mode:
  • ∘ the air inlet of the compressor is designed to receive a flow of expanded air from the turbine via at least one heat exchanger, called an intermediate reheating exchanger, suitable for reheating the expanded air delivered by the turbine in contact with an air flow chosen from an outside air flow, a stale air flow to be evacuated out of the cabin, and their mixtures,
  • ∘ the compressed and heated air delivered to the outlet of the turbocharger compressor passes through a first circuit ("hot pass") of a heat exchanger, called the cabin heating exchanger, adapted to heat a supply air flow of the cabin of the vehicle passing through a second circuit (“cold pass”) of the cabin heating exchanger, an outlet of the first circuit of the cabin heating exchanger being connected to the air inlet of the turbine,
• said intermediate cooling exchanger and said at least one intermediate reheating exchanger are formed from one and the same heat exchanger,
• in a second variant in heating mode:
  ∘ said set of conduits and controlled valves is adapted to be able to be controlled also according to an operating mode chosen from a heating mode in which:
  • ∘ a flow of stale air to be evacuated from the cabin is supplied to the inlet of the turbocharger compressor,
  • ∘ the compressed and heated air delivered at the outlet of the compressor of the turbocharger, passes through at least one exchanger interposed between the air outlet of the compressor of at least one turbocharger and the air inlet of the turbine of the turbocharger,
  • ∘ and the air delivered to the outlet of the turbocharger turbine is connected to an outlet to be discharged to the outside,
• it comprises a regulation unit adapted to control the speed of rotation of the electric motor of each turbocharger as a function of a set thermal power to be delivered to the cabin of the vehicle,
• at least one - in particular each - turbocharger has a maximum diameter (volute) of less than 400 mm, for example between 300 mm and 400 mm, in particular of the order of 360 mm,
• at least one - in particular each - turbocharger has a weight of less than 50 kg, for example between 20 kg and 50 kg, in particular of the order of 30 kg,
• at least one - in particular each - turbocharger is suitable for being able to be controlled with a maximum rotation speed greater than 50,000 rpm, in particular between 50,000 rpm and 100,000 rpm, for example of the order of 65,000 rpm min,
• at least one - in particular each - air cycle device comprises a device for extracting, upstream of the air inlet of the turbine, the humidity of the compressed air delivered, in cooling mode, at the compressed air outlet of the compressor; in certain embodiments, this extraction device comprises a moisture extraction loop successively comprising a first circuit ("hot pass") of a reheating heat exchanger connected to the intermediate cooling exchanger in order to be able to receive the flow rate of 'compressed (and cooled) air delivered by this intermediate cooling exchanger, a first circuit ("hot pass") of a condenser heat exchanger, a liquid water extraction device, a second circuit ("cold pass" ) of the heat exchanger heater connected to the liquid water extraction device to be able to receive the air flow delivered downstream of the liquid water extraction device to heat it by the compressed air flow supplying the first circuit of the reheater heat exchanger, a second circuit ("cold pass") of the condenser heat exchanger connected to the outlet of the turbine to be able to receive the flow of expanded cold air delivered é by the air outlet of the turbine, and cool the flow of compressed air passing through the first circuit of the condenser heat exchanger so as to condense the humidity present in this flow of compressed air.

Thus, in a method and a vehicle according to the invention, the air conditioning is obtained by at least one motorized turbocharger, the compressor of which receives air at a pressure greater than or equal to atmospheric pressure. This results in particular not only in a simplification of the architecture and components without the use of two-phase heat transfer fluid, but also in the possibility of considerably reducing the air flow in the loop and the dimensions of the pipes and valves.

In cooling mode, the air flow through the loop can be limited to the flow of fresh air to be supplied to the cabin. It is thus typically divided by 2 with respect to the air flow through the reverse loop of the second type of state of the art solution mentioned above. In addition, the pressures in the loop typically go from a value of the order of 0.5 10 ⁵ Pa to a value of the order of 3 10 ⁵ Pa, that is to say they are multiplied by 6. As a result, the diameter of the air circulation ducts in the loop can be divided by a factor typically equal to $\sqrt{12}=3.4.$

This also results in the possibility of using the air cycle loop and at least one turbocharger of each air cycle device as a heat pump for heating the cabin, in particular by reversing the direction of air circulation. in the loop. It turns out that, with a direct loop air cycle in accordance with the invention, the pressures and the operating points of the compressor and of the turbine of the turbocharger are substantially the same in cooling mode and in heating mode. . It is thus possible to generate a hot thermal power with an efficiency greater than 1. The inventors have thus determined that it is possible to obtain a coefficient of performance typically of the order of 1.25, that is to say. say a gain of 25% to 30% compared to an electric heater. Also, the vast majority of components used in cooling mode are reused in heating mode. In addition, it is possible to recover in the intermediate exchanger in heating mode the calories of the stale air discharged from the cabin, or in cooling mode the frigories of the stale air discharged from the cabin.

In addition, the cooling of the exchangers can be carried out using simple electric fans.

In certain embodiments of a method and of a vehicle according to the invention, each air cycle device comprises one and only one turbocharger, and can be configured and adjusted during manufacture in the factory, installation on board the. vehicle being limited to the connection of the air inlets and air outlets of the air cycle device to the corresponding pipes of the vehicle. The number of air cycle device (s) and / or the number of turbocharger (s) can be adjusted according to the thermal power required for each vehicle. In particular, a vehicle according to the invention for example advantageously comprises a plurality of air cycle devices - in particular between 2 and 10 air cycle devices each comprising one and only one turbocharger. Thus, the inventors have demonstrated that it is in reality preferable to provide several air cycle devices of smaller dimensions each incorporating a motorized turbocharger driven at high rotational speed which, although more expensive and complex to manufacture, makes it possible to obtaining savings in energy consumption and ease of installation on board a land vehicle such as a rail vehicle, largely offsetting the additional manufacturing cost of the turbochargers.

The invention also extends to a method for supplying air at controlled temperature implemented in a land vehicle according to the invention. It also extends to a land vehicle in which a temperature-controlled air supply method according to the invention is implemented.

The invention also relates to a temperature-controlled air supply method and a land vehicle characterized, in combination or not, by all or some of the characteristics mentioned above or below. Whatever the formal presentation which is given, unless explicitly indicated otherwise, the various characteristics mentioned above or below should not be considered as closely or inextricably linked to each other, the invention being able to relate to only one of these structural or functional characteristics, or only part of one of these structural or functional characteristics, or any grouping, combination or juxtaposition of all or part of these structural or functional characteristics.

• la figure 1 est un schéma synoptique fonctionnel illustrant un dispositif à cycle à air d'un véhicule selon un premier mode de réalisation de l'invention mettant en œuvre un procédé selon un premier mode de réalisation de l'invention en mode de refroidissement,
• la figure 2 est un schéma synoptique fonctionnel du dispositif à cycle à air de la figure 1 en mode de chauffage,
• la figure 3 est un schéma synoptique fonctionnel illustrant un dispositif à cycle à air d'un véhicule selon un deuxième mode de réalisation de l'invention mettant en œuvre un procédé selon un deuxième mode de réalisation de l'invention en mode de refroidissement,
• la figure 4 est un schéma synoptique fonctionnel du dispositif à cycle à air de la figure 3 en mode de chauffage.

Other aims, characteristics and advantages of the invention will become apparent on reading the following description given without limitation and which refers to the appended figures in which:

• the figure 1 is a functional block diagram illustrating an air cycle device of a vehicle according to a first embodiment of the invention implementing a method according to a first embodiment of the invention in cooling mode,
• the figure 2 is a functional block diagram of the air cycle device of the figure 1 in heating mode,
• the figure 3 is a functional block diagram illustrating an air cycle device of a vehicle according to a second embodiment of the invention implementing a method according to a second embodiment of the invention in cooling mode,
• the figure 4 is a functional block diagram of the air cycle device of the figure 3 in heating mode.

The air cycle device according to the invention shown in the figures allows environmental control (air conditioning by cooling or heating) of a cabin 10 of a land vehicle according to the invention. It comprises a turbocharger 11 powered by an electric motor 12 driving a shaft 13 of the turbocharger 11 coupled to a rotary turbine 14 and to a rotary compressor 15. Such a motorized turbocharger 11 is known in itself and can be the subject of numerous variant embodiments, in particular as regards the type of turbine (axial or radial), the type of compressor (axial or radial), the type electric motor, the assembly of the shaft and the bearings (for example aerodynamic bearings or magnetic bearings), the relative arrangement of the wheels and / or the motor ...

• turbine 14 et compresseur 15 de type radial,
• paliers aérodynamiques ou magnétiques,
• vitesse de rotation maximale comprise entre 50000 tr/min et 100000 tr/min, par exemple de l'ordre de 65000 tr/min,
• taux de compression maximal du compresseur : compris entre 2,5 et 5, notamment de l'ordre de 3,2,
• taux de détente maximal de la turbine : compris entre 2 et 5,
• moteur électrique : de puissance nominale comprise entre 10 kW et 100 kW, notamment de l'ordre de 40 kW,
• diamètre maximum de volute (volute du compresseur 15) inférieur à 500 mm, par exemple compris entre 300 mm et 500 mm, notamment de l'ordre de 360 mm,
• diamètre maximum de roue du compresseur 15 inférieur à 250 mm, par exemple compris entre 100 et 250 mm, notamment de l'ordre de 150 mm,
• poids inférieur à 50 kg, par exemple compris entre 15 kg et 50 kg, notamment de l'ordre de 30 kg,
• diamètre des paliers, notamment dans le cas de paliers à air, compris entre 30 mm et 50 mm, notamment de l'ordre de 40 mm.

In the case of a land vehicle such as a rail vehicle, for example for high-speed trains, the turbocharger 11 can advantageously be chosen with the following characteristics, given solely by way of non-limiting example:

• turbine 14 and compressor 15 of the radial type,
• aerodynamic or magnetic bearings,
• maximum speed of rotation between 50,000 rpm and 100,000 rpm, for example of the order of 65,000 rpm,
• maximum compression ratio of the compressor: between 2.5 and 5, in particular around 3.2,
• maximum turbine expansion rate: between 2 and 5,
• electric motor: with a nominal power of between 10 kW and 100 kW, in particular of the order of 40 kW,
• maximum volute diameter (compressor volute 15) less than 500 mm, for example between 300 mm and 500 mm, in particular of the order of 360 mm,
• maximum wheel diameter of the compressor 15 less than 250 mm, for example between 100 and 250 mm, in particular of the order of 150 mm,
• weight less than 50 kg, for example between 15 kg and 50 kg, in particular of the order of 30 kg,
• diameter of the bearings, in particular in the case of air bearings, between 30 mm and 50 mm, in particular of the order of 40 mm.

The turbine 14 has an air inlet 16 and an outlet 17 for expanded and cooled air. The compressor 15 comprises an air inlet 18 and an outlet 19 of compressed and heated air.

A first circuit of an air / air intermediate exchanger 20 is interposed between the compressor 15 and the turbine 14.

This intermediate exchanger 20 has a second air circuit supplied by an air flow driven by at least one electric fan 21. This air flow can be formed by a flow of ambient outside air taken from outside the vehicle at ambient temperature, of a flow of stale air discharged from the cabin 10 (in particular for the renewal of the air. in the cabin 10) by a pipe 34, and their mixtures. The air flow passing through the second air circuit of the intermediate exchanger 20 is therefore at a temperature between the temperature outside the vehicle and the temperature prevailing in the cabin 10. After passing through the second air circuit of the intermediate exchanger 20, this air flow is rejected to the outside.

A moisture extraction loop 22 is interposed between the first circuit of the intermediate exchanger 20 and the turbine 14. This humidity extraction loop 22 successively comprises, from the intermediate exchanger 20, a first circuit of an air / air heat exchanger 23, a first circuit of an air / air condenser heat exchanger 24, a device 25 for extracting liquid water, a second circuit of the heater 23, the outlet of which is connected to the inlet of the turbine 14. The outlet of the turbine 14 is connected to a second circuit of the condenser 24, the latter supplying a chamber of mixture 26 supplying the cabin 10. The mixing chamber 26 can also receive, on the one hand, a flow of recirculation air extracted from the cabin 10 by electric fans 27, 28 and, on the other hand, a flow of fresh air taken from outside the vehicle, thanks to these electric fans 27, 28 if the cold thermal power required in the cabin 10 is such that the air flow delivered by the turbine 14 is not sufficient to cover the need for renewal of air in the cabin 10.

The air outlet 19 of the compressor 15 can be connected to the air inlet 16 of the turbine 14 via a first circuit of an air / air heat exchanger, called the cabin heating exchanger 32, the second circuit of which is interposed between the mixing chamber 26 and the cabin 10.

Each heat exchanger 20, 23, 24, 32 allows heat transfer between its first circuit (first "pass") and its second circuit (second "pass"), according to the temperature difference of the air flows respectively passing through these two circuits.

A regulation unit 30 comprising in particular an electronic and / or computer automation and a power converter allows the control of the electric motor 12 at a speed of rotation determined by a servo-control according to the cold or hot thermal power to be delivered in the cabin. 10, itself determined as a function of the temperature measured in the cabin 10 by a temperature sensor 31, and of a setpoint temperature determined by a user of the vehicle. This control is carried out by the regulation unit 30 according to a closed-loop servo-control with a law for controlling the speed of rotation of the motor as a function of the temperature of the air delivered to the inlet of the mixing chamber 26, itself determined as a function of the set temperature, of the temperature measured in the cabin 10, and of the temperatures and air flow rates entering the mixing chamber 26 and leaving the latter. The flow of air entering the cabin 10 is measured by a flow sensor 56. The air flow leaving the cabin 10 is measured by a flow sensor 57. These flow rates are also controlled by the regulation unit 30, in particular as a function of a quantity of fresh renewal air to be brought into the cabin 10, which can be determined itself by means of a carbon dioxide sensor 37. in cabin 10, making it possible to estimate the occupancy rate of the latter.

The air cycle device also includes a set of conduits and controlled valves, and the control unit is also connected to each of the controlled valves to control the state thereof so as to select an operating mode of the cycle device. air from a cooling mode and a heating mode, this operating mode being able to be selected manually by the user or determined automatically by the control unit itself as a function in particular of the difference between the temperature measured at the inside the cabin 10 and the outside temperature measured by a temperature sensor 33 connected to the control unit 30.

In the first embodiment shown in figures 1 and 2 , the air inlet 18 of the compressor 15 comprises a three-way controlled valve 40, an inlet 41 of which is connected by a pipe 42 to the first circuit of the intermediate exchanger 20, an inlet 43 is supplied with fresh outside air 58, and having an outlet 44 connected to the air inlet 18 of the compressor 15.

The air outlet 19 of the compressor 15 is connected to an inlet 46 of a controlled three-way valve 45, an outlet 47 of which is connected to the pipe 42 leading to the first circuit of the intermediate exchanger 20 (pipe 42 connecting the inlet air 18 from the compressor 15 to the first circuit of the intermediate exchanger 20), and an outlet 48 of which is connected to the first circuit of the cabin heating exchanger 32.

A controlled valve 49 is interposed between the air outlet 17 of the turbine 14 and the mixing chamber 26, for example between the outlet of the second circuit of the condenser heat exchanger 24 and the inlet of the mixing chamber 26. .

A controlled three-way valve 50 is interposed between the first circuit of the intermediate exchanger 20 and a pipe 51 connecting the air outlet 17 of the turbine 14 to the first circuit of the heat exchanger 24. condenser. This valve 50 comprises an inlet 52 connected to the pipe 51; an output 53 connected to the input of the moisture extraction loop 22, that is to say to the first circuit of the reheater heat exchanger 23; and an inlet / outlet 54 connected to the first circuit of the intermediate exchanger 20.

A controlled valve 55 makes it possible to supply the mixing chamber 26 with fresh outside air 58.

The control logic of such a unit 30 for regulating an air cycle device is, moreover, well known in itself and can be the subject of all variant embodiments.

In the figures, the pipes in which the air circulates are shown in thicker lines than those in which the air does not circulate, depending on the operating mode selected.

In cooling mode, the control unit 30 places the various valves 40, 45, 49, 50, 55 controlled in the state shown figure 1 .

The valve 40 connects its inlet 43 to its outlet 44 and its inlet 41 is closed. The air inlet 18 of the compressor 15 receives fresh outside air 58 taken directly at atmospheric pressure or at the dynamic pressure resulting from the movement of the vehicle at a pressure greater than atmospheric pressure. It should be noted in this regard that the air cycle device is free from any other electric compressor, the compression of the air in the loop being obtained exclusively and entirely by the compressor 15 of the turbocharger 11.

The valve 45 connects its inlet 46 to its outlet 47 connected to the first circuit of the intermediate exchanger 20, and its other outlet 48 is closed. The air outlet 19 of the compressor 15 supplies the first circuit of the intermediate exchanger 20 which constitutes the hot pass of this intermediate exchanger 20, the flow of compressed air heated by the compressor 15 being cooled in this intermediate exchanger 20 by the air flow circulating in the second circuit of the intermediate exchanger 20, which constitutes the cold pass of the latter. The second air circuit of the intermediate exchanger 20 is supplied by an air flow driven by at least one electric fan 21. This air flow can be chosen among an outside air flow 58 taken from outside the vehicle at ambient temperature, a flow of stale air discharged from the cabin 10 (in particular for the renewal of the air in the cabin 10) via the pipe 34 , and their mixtures. The air flow passing through the second air circuit of the intermediate exchanger 20 is therefore at a temperature between the temperature outside the vehicle and the temperature prevailing in the cabin 10. After passing through the second air circuit of the intermediate exchanger 20, this air flow is rejected to the outside through an outlet 59.

The flow of compressed and cooled air at the outlet of the first circuit of the intermediate exchanger 20 is supplied to the first circuit of the heater 23 then to the device 25 for extracting humidity then to the second circuit of the heater 23 then to the air inlet 16 of the turbine 14 in which it is cooled and expanded. The intermediate exchanger 20 is therefore, in this cooling mode, an intermediate exchanger 20 for cooling the compressed air delivered by the compressor 15. The valve 50 connects the first circuit of the intermediate exchanger 20 to the first circuit of the heater 23. , and the inlet 52 of the valve 50 connected to the outlet pipe 51 of the turbine 14 is closed.

The expansion in the turbine 14 also makes it possible to create a mechanical work which is added to that of the electric motor to drive the compressor in rotation, and to initiate the cycle on starting. The turbine 14 thus makes it possible to increase the mechanical work delivered to the compressor 15, the speed of rotation of the motor 12 being adjusted by the control unit 30 to obtain a temperature value at the outlet of the turbine 14 suitable for cooling the machine. air in cabin 10, typically of the order of -10 ° C.

The valve 49 is opened so that the air leaving the turbine 14 feeds the mixing chamber 26 via the second circuit of the condenser 24. The valve 55 is assumed to be closed for the nominal operating point. It can be more or less open depending on a quantity of outdoor fresh air flow 58 necessary to supply the cabin with oxygen. The flow of air cooled and expanded by the turbine 14 passing through the second circuit of the condenser 24 makes it possible to lower the temperature of the flow of air passing through the first circuit of this condenser 24 up to a value allowing water condensation. The water extracted by the moisture extraction device 25 is advantageously introduced via a pipe 38 into the second circuit of the intermediate exchanger 20 in order to be evaporated there and to help lower the cooling temperature. The heater 23 then makes it possible to recover the heat energy of the air flow at the outlet of the intermediate exchanger 20 by heating the air flow leaving the first circuit of the condenser 24 before its introduction into the turbine 14.

The mixing chamber 26 is also supplied with recirculation air coming from the cabin via the pipe 29 by the fans 27, 28 which also supply the cabin 10 with air coming from the mixing chamber 26 via the second circuit of the exchanger. 32 cabin heater which is inactive, the first circuit of this cabin heater exchanger 32 not being supplied.

Thus, in cooling mode, the air cycle device performs a direct open loop air cycle from the motorized turbocharger 11. The pressure in the loop corresponds to that delivered by the compressor 15, greater than atmospheric pressure, typically of the order of 3 10 ⁵ Pa.

In heating mode, the control unit 30 places the various valves 40, 45, 49, 50, 55 controlled in the state shown figure 2 .

The valve 40 connects its inlet 41 to its outlet 44 and its inlet 43 is closed. The valve 50 connects its inlet 52 connected to the air outlet 17 of the turbine 14 to the inlet / outlet 54 connected to the first circuit of the intermediate exchanger 20, and the outlet 53 of the valve 50 connected to the heater 23 is closed. Valve 49 is closed. The air inlet 18 of the compressor 15 thus receives a flow of expanded air coming from the turbine 14 via the first circuit of the intermediate exchanger 20, suitable for heating the expanded and cooled air delivered by the turbine 14 in contact with an air flow passing through the second circuit of the intermediate exchanger 20, the latter being at a temperature between the temperature outside the vehicle and the temperature prevailing in the cabin 10.

A pipe 35 is connected in parallel to the air inlet 18 of the compressor 15, that is to say in the example shown in the pipe 42, preferably via a valve 36 to allow the introduction of fresh outside air 58 into the loop by suction by the compressor 15 as a function of the leaks occurring in the loop and in the turbocharger 11. The pressure of the air at the air inlet 18 of the compressor 15 is equal to atmospheric pressure.

The valve 45 connects its inlet 46 to its outlet 48 connected to the first circuit of the cabin heating exchanger 32, and its other outlet 47 is closed. The air outlet 19 of the compressor 15 is connected to the air inlet 16 of the turbine 14 via the first circuit of the cabin heating exchanger 32, the second circuit of which is interposed between the mixing chamber 26 and the cabin 10, so that a flow of air delivered by the mixing chamber 26 is heated in this cabin heating exchanger 32 by the calories of the hot compressed air passing through the first circuit of the exchanger 32 of cabin heating. This air flow delivered by the mixing chamber 26 is formed by the mixing of the recirculation air coming from the cabin 10 connected to the mixing chamber by a pipe 29 and the fresh outside air 58 supplied into the mixing chamber 26 by the valve 55 which is open. The fans 27, 28 ensure the mixing and flow of the air at the outlet of the mixing chamber 26.

After passing through the turbine 14, the air is expanded and cooled to a temperature much lower than the temperature of the cabin and the outside temperature, typically of the order of -40 ° C. The expansion in the turbine is accompanied the creation of a mechanical work which is added to that of the electric motor 12 to drive the compressor 15 in rotation.

The first circuit of the air / air intermediate exchanger 20 is interposed between the turbine 14 and the compressor 15. It receives the flow of expanded and cooled air from the turbine 14 in order to heat it before delivering it to the inlet. air 18 of the compressor 15. The second air circuit of the intermediate exchanger 20 is supplied by an air flow driven by at least one electric fan 21. This air flow can be chosen from an external air flow 58 taken from outside the vehicle at ambient temperature, a stale air flow discharged from the cabin 10 (in particular for the renewal of the air in the cabin 10) via line 34, and their mixtures. The air flow passing through the second circuit air from the intermediate exchanger 20 is therefore at a temperature between the temperature outside the vehicle and the temperature prevailing in the cabin 10. After passing through the second air circuit of the intermediate exchanger 20, this air flow is rejected to the outside through the outlet 59. In heating mode, the intermediate exchanger 20 is therefore an intermediate reheating exchanger 20.

Tables 1 and 2 below give, by way of nonlimiting example, various typical values of flow rate, pressure and temperature at the air inlets and outlets of the turbine 14 of the compressor 15 of the turbocharger 11 which can be obtained in the first embodiment of the invention. Table 1 Cooling mode Settings Temperature Pressure (10 ⁵ Pa) Debit Compressor input 35 ° C 1 0.4 kg / s Compressor output 183 ° C 3.1 0.4 kg / s Turbine inlet 35 ° C 3.05 0.39 kg / s Turbine output -19 ° C 1.05 0.39 kg / s Heating mode Settings Temperature Pressure (10 ⁵ Pa) Debit Compressor input 0 ° C 1 0.3 kg / s Compressor output 100 ° C 2.5 0.3 kg / s Turbine inlet 10 ° C 2.45 0.3 kg / s Turbine output -40 ° C 1.05 0.3 kg / s

Other typical temperature values are shown on the figures 1 and 2 . Thus, in heating mode, the air cycle device performs an inverted closed loop cycle forming a heat pump with the turbocharger 11, the stages of this turbocharger 11 having substantially the same operating conditions as in cooling mode, the ventilation circuits being the same as in the cooling mode. The hot thermal power is thus generated with an efficiency greater than 1.

In addition, the operating pressures in the different parts of the air cycle device are all greater than atmospheric pressure, which makes it possible to reduce the sections and dimensions of the pipes and the components (valves, volutes and impellers of the turbocharger. .), and therefore the overall size and cost of each air cycle device.

The second embodiment shown in figures 3 and 4 differs from the first embodiment in that it makes it possible to dispense with the cabin heating exchanger 32, the intermediate exchanger 20 being used for heating. In addition, this second embodiment also makes it possible to reduce the number of valves.

The three-way valve 40 at the inlet 18 of the compressor 15 of the first embodiment is replaced by a four-way valve 60 connected to an outside fresh air inlet 58, to the pipe 34 for taking air from the cabin 10, by a pipe 64 to the inlet 18 of the compressor 15, and to a pipe 61 which connects it to the inlet of the second circuit of the intermediate exchanger 20. The valve 55 at the inlet of the mixing chamber 26 of the first embodiment is replaced by a four-way valve 62 connected to an inlet 58 of fresh outside air, to a pipe 63 connected to the outlet of the second circuit of the valve. 'Intermediate exchanger 20, at an air outlet 59 outside the cabin 10, and via a pipe 67 at the inlet of the mixing chamber 26. The valve 49 at the outlet of the condenser 24 of the first embodiment is replaced by a three-way valve 65 having an outlet towards the mixing chamber 26 and another outlet towards a mouth 59 for discharging the air out of the cabin. 10.

In cooling mode, the control unit 30 places the various valves 60, 62, 65 controlled in the state shown figure 3 . The operation is similar to the cooling mode of the first embodiment.

The valve 60 connects the air inlet 18 of the compressor 15 to the fresh outside air inlet 58 at the dynamic pressure resulting from the movement of the vehicle at a pressure greater than atmospheric pressure. It also connects the pipe 34 coming from the cabin 10 to the pipe 61 in communication with the second circuit of the intermediate exchanger 20.

The air outlet 19 of the compressor 15 supplies the first circuit of the intermediate exchanger 20 which constitutes the hot pass of this intermediate exchanger 20, the flow of compressed air heated by the compressor 15 being cooled in this intermediate exchanger 20 by the air flow circulating in the second circuit of the intermediate exchanger 20, which constitutes the cold pass of the latter. The second air circuit of the intermediate exchanger 20 is supplied by an air flow driven by at least one electric fan 21. This air flow can be chosen from an outside air flow 58 taken from outside the vehicle at ambient temperature, an air flow evacuated from the cabin 10 via the pipe 34, and their mixtures. The air flow passing through the second air circuit of the intermediate exchanger 20 is therefore at a temperature between the temperature outside the vehicle and the temperature prevailing in the cabin 10. After passing through the second air circuit of the exchanger 20 intermediate this air flow supplied by the pipe 63 to the valve 62 which puts it in communication with the outlet opening 59, so that this air flow is rejected to the outside. The intermediate exchanger 20 is therefore, in this cooling mode, an intermediate exchanger 20 for cooling the compressed air delivered by the compressor 15.

The flow of compressed and cooled air at the outlet of the first circuit of the intermediate exchanger 20 follows the same circuit as in the first embodiment up to the valve 65 which delivers the flow of cooled air to the chamber 26 of mixed.

The expansion in the turbine 14 makes it possible, here again, to create a mechanical work which is added to that of the electric motor 12 to drive the compressor 15 in rotation, and to initiate the cycle on starting. The turbine 14 thus makes it possible to increase the mechanical work delivered to the compressor 15, the speed of rotation of the motor 12 being adjusted by the control unit 30 to obtain a temperature value at the outlet of the turbine 14 suitable for cooling the machine. air in cabin 10, typically of the order of -10 ° C.

The valve 65 is open so that the air leaving the turbine 14 feeds the mixing chamber 26 via the second circuit of the condenser 24. The valve 62 is assumed to be closed between the fresh air inlet 58 and the chamber 26 of the condenser. mixture for the nominal operating point. It can be more or less open depending on a quantity of outdoor fresh air flow 58 necessary to supply the cabin with oxygen.

The mixing chamber 26 is also supplied with recirculation air coming from the cabin via the duct 29 by the fans 27, 28 which also supply the cabin 10 with air coming from the mixing chamber 26.

Thus, in cooling mode, the air cycle device performs a direct open loop air cycle from the motorized turbocharger 11. The pressure in the loop corresponds to that delivered by the compressor 15, greater than atmospheric pressure, typically of the order of 3 10 ⁵ Pa.

On the other hand, in the heating mode, the operation of the air cycle device according to the second embodiment is different from that of the first embodiment. In heating mode, the control unit 30 places the various valves 60, 62, 65 controlled in the state shown figure 4 .

The valve 60 receives air in line 34 from the cabin 10 and directs a portion of this air, corresponding to the air flow to be evacuated from the cabin to the outside for the renewal of air in the cabin, to the air inlet 18 of the compressor 15 via the pipe 64. This air flow follows the same circuit as in the cooling mode but, at the outlet of the second circuit of the condenser 24, the valve 65 directs this air flow to the outlet 59 to discharge it outside the vehicle.

The air coming from the second circuit of the intermediate exchanger 20 has been heated by the flow of compressed air delivered by the compressor 15 into the first circuit of this intermediate exchanger 20. This flow of heated air delivered in the duct 63 is directed by the valve 62 at the inlet of the mixing chamber 26 to produce the calories allowing the heating of the cabin. This heated air flow comes from the air flow supplied to the inlet of the second heating circuit. the intermediate exchanger 20 which can be formed by a flow of fresh air coming from an inlet 58 of outside fresh air and / or a flow of recirculating air coming from the cabin via the pipe 61 and valve 60.

Thus, in this second embodiment, in heating mode, the main air circuit circulating in the turbocharger 11 and a flow of air discharged to the outside, which may correspond to the flow of air to be extracted from the cabin 10 for the renewal of oxygen in the cabin 10, and which serves to heat the air flow supplying the mixing chamber 26 and therefore the cabin by virtue of the intermediate exchanger 20 which acts as a heating exchanger.

It should be noted that in a variant not shown of this second embodiment, the air inlet 18 of the compressor 15 can be supplied directly by a specific air intake coming from the cabin 10, for example for the discharge. of stale air to the outside, along a different duct from the recirculation and heating air passing through the second circuit of the intermediate exchanger.

Table 3 below gives, by way of nonlimiting example, various typical values of flow rate, pressure and temperature at the air inlets and outlets of the turbine 14 of the compressor 15 of the turbocharger 11 that can be obtained in the second embodiment of the invention in heating mode. Table 3 Heating mode Settings Temperature Pressure (10 ⁵ Pa) Debit Compressor input 20 ° C 1 0.3 kg / s Compressor output 130 ° C 2.5 0.3 kg / s Turbine inlet 30 ° C 2.45 0.3 kg / s Turbine output -20 ° C 1 0.3 kg / s

In the cooling mode, the values given in Table 1 above for the first embodiment can be obtained similarly with the second embodiment.

An air cycle device of a vehicle according to the invention can in particular be in the form of a compact air conditioning unit (ECS) in one piece integrating all of its components.

• plusieurs dispositifs à cycle à air, chaque dispositif à cycle à air comportant au moins un turbocompresseur et au moins un jeu d'échangeurs de chaleur pour au moins un circuit d'air ;
• ou un unique dispositif à cycle à air comprenant un unique circuit d'air et un unique jeu d'échangeurs de chaleur et une pluralité de turbocompresseurs, les différents turbocompresseurs étant en communication de fluide avec ce même circuit d'air ;
• ou un unique dispositif à cycle à air avec un unique turbocompresseur en communication de fluide avec une pluralité de circuits d'air et une pluralité de jeux d'échangeurs de chaleur
• ou un unique dispositif à cycle à air comportant un unique turbocompresseur en communication de fluide avec un unique circuit d'air comprenant un unique jeu d'échangeurs de chaleur.

The same ECS air conditioning unit of a vehicle according to the invention may include:

• several air cycle devices, each air cycle device comprising at least one turbocharger and at least one set of heat exchangers for at least one air circuit;
• or a single air cycle device comprising a single air circuit and a single set of heat exchangers and a plurality of turbochargers, the different turbochargers being in fluid communication with this same air circuit;
• or a single air cycle device with a single turbocharger in fluid communication with a plurality of air circuits and a plurality of sets of heat exchangers
• or a single air cycle device having a single turbocharger in fluid communication with a single air circuit including a single set of heat exchangers.

Such a reversible air conditioning unit (DHW) can be multiplied on board a land vehicle according to the invention as a function of the cold or hot thermal power required in the cabin 10. A single DHW air conditioning group can be used in land vehicles according to the invention very diverse, for applications in very hot and / or very humid areas, or on the contrary very cold and / or very dry. A land vehicle according to the invention comprising a plurality of air cycle devices and / or a plurality of air conditioning units also makes it possible to ensure at least partial maintenance of the environmental control function in the cabin 10 in the event of failure of one of the air cycle devices and / or one of the air conditioning units. It should be noted in particular that it is possible to increase the speed of rotation of each other turbocharger to overcome the deficiency of one of the turbochargers, if the dimensioning of the installation is such that the nominal operating speed of the various turbochargers is less than their maximum speed.

A vehicle according to the invention comprising a plurality of air cycle devices advantageously also comprises a central control unit making it possible to control the various air cycle devices and their respective regulation units. Nothing prevents providing that the functions of the control units of the various air cycle devices are at least partly centralized in such a central control unit. Likewise, a vehicle according to the invention comprising a plurality of air conditioning groups advantageously also comprises a central control unit making it possible to control the various air conditioning groups, in particular the various air conditioning groups associated with the same cabin 10 of the vehicle.

It goes without saying that the invention can be the subject of very many variant embodiments with respect to the embodiment described above and shown in the figures. In particular, at least one cooling loop with liquid or two-phase coolant can be associated in series or in parallel on at least one air circuit of at least one air cycle device and / or at least one group. for DHW air conditioning of a vehicle according to the invention, for cooling heat sources on board the vehicle, for example electric or electronic power circuits.

The invention applies most particularly advantageously to a railway vehicle, in particular for passenger transport trains. It nevertheless applies to all other land vehicles in which the same technical problems arise, in particular rolling vehicles (motor cars, buses, trucks, etc.) and vehicles moving on water (ships).

It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of the invention as claimed. Therefore, the present embodiments should be considered by way of illustration, but may be modified within the field defined by the scope of the appended claims.

Claims (13)

1. Method for supplying air at a controlled temperature to a cabin (10) of a surface vehicle in which at least one air cycle device is used, comprising:

   - at least one turbocompressor (11) comprising:

   ∘ a rotating compressor (15),

   ∘ a rotating turbine (14),

   ∘ a shaft (13) coupling the turbine and the compressor such that the turbine is able to rotationally drive the compressor,

   ∘ an air inlet (18) of the compressor,

   ∘ an air outlet (19) of the compressor delivering an airflow compressed by the compressor,

   ∘ an air inlet (16) of the turbine arranged to receive a compressed airflow from the compressor,

   ∘ an air outlet (17) of the turbine delivering an expanded cold airflow,

   - at least one exchanger (20, 23, 24, 32) interposed between the air outlet (19) of the compressor of at least one turbocompressor and the air inlet (16) of the turbine of at least one turbocompressor,

   characterised in that:

   - use is made of at least one turbocompressor (11) of at least one air cycle device comprising an electric motor (12) coupled to the compressor (15) so as to be able to deliver mechanical power to the compressor (15),

   - the air inlet (18) of the compressor (15) of at least one turbocompressor of at least one air cycle device is arranged to receive air at a pressure greater than or equal to atmospheric pressure,

   - each turbocompressor (11) of each air cycle device is associated with a set of controlled valves (40, 45, 49, 50, 55) and conduits, adapted to be able to be controlled in one operating mode selected at least from:

   ∘ a heat pump heating mode in which:

   ▪ the air inlet (18) of the compressor (15) is arranged to receive an expanded airflow from the turbine (14) via at least one heat exchanger, named intermediate heating exchanger (20), adapted to heat the expanded air delivered by the turbine (14) in contact with at least one air stream selected from an external air stream, a foul air stream to be vented out of the cabin, and mixtures thereof,

   ▪ the compressed and heated air delivered to the outlet (19) of the compressor (15) of the turbocompressor passes through a first circuit of a heat exchanger, named cabin heat exchanger, adapted to heat an airflow for supply to the cabin (10) of the vehicle passing through a second circuit of the cabin heat exchanger, an outlet of the first circuit of the cabin heat exchanger being connected to the air inlet (16) of the turbine,

   ∘ a cooling mode in which:

   ▪ the air inlet (18) of the compressor (15) is arranged to receive air external to the vehicle,

   ▪ the compressed air outlet (19) of the compressor (15) is connected to at least one heat exchanger, named intermediate exchanger (20), delivering a compressed air stream cooled by at least one air stream selected from an external air stream, a foul air stream to be vented out of the cabin, and mixtures thereof.
2. Method according to claim 1, characterised in that the turbine (14) of each turbocompressor is arranged to deliver an expanded airflow at a pressure greater than or equal to atmospheric pressure.
3. Method according to any one of claims 1 or 2, characterised in that in the cooling mode, the expanded cold airflow delivered by the air outlet (17) of the turbine is introduced into the cabin (10) of the vehicle.
4. Method according to one of claims 1 to 3, characterised in that in the heating mode, said airflow for supply to the cabin (10) of the vehicle is formed by at least one airstream selected from an external air stream, a recirculation airstream from the cabin of the vehicle, and mixtures thereof.
5. Method according to one of claims 1 to 4, characterised in that said set of controlled valves (40, 45, 49, 50, 55) and conduits is adapted to be able to be likewise controlled in an operating mode selected from a heating mode in which:

   - a foul air stream to be vented out of the cabin is supplied to the inlet of the compressor of the turbocompressor,

   - the compressed and heated air delivered to the outlet (19) of the compressor (15) of the turbocompressor passes through at least one exchanger (20, 23, 24) interposed between the air outlet of the compressor of at least one turbocompressor and the air inlet of the turbine of the turbocompressor,

   - and the air delivered to the outlet of the turbine of the turbocompressor is connected to an outlet orifice (59) to be ejected to the outside.
6. Method according to one of claims 1 to 5, characterised in that the rotational speed of the electric motor (12) of each turbocompressor (11) is controlled based on a set thermal power to be delivered to the cabin (10) of the vehicle.
7. Method according to one of claims 1 to 6, characterised in that the moisture of the compressed air delivered to the air inlet (16) of the turbine (14) is extracted upstream of this air inlet (16).
8. Method according to claim 7, characterised in that the moisture is extracted by a moisture extraction loop (22) comprising a first circuit of a heating heat exchanger (23) receiving the compressed air stream from the intermediate cooling exchanger (20), a first circuit of a condensing heat exchanger (24), a liquid water extraction device (25), a second circuit of the heating heat exchanger (23) receiving the airflow delivered downstream of the liquid water extraction device (25) to heat it by the compressed airflow supplying the first circuit of the heating heat exchanger (23), and a second circuit of the condensing heat exchanger (24) receiving the expanded cold airflow delivered by the air outlet (17) of the turbine (14) to cool the compressed airflow passing through the first circuit of the condensing heat exchanger (24) so as to condense the moisture present in this compressed airflow.
9. Surface vehicle comprising at least one air cycle device, comprising:

   - at least one turbocompressor (11) comprising:

   ∘ a rotating compressor (15),

   ∘ a rotating turbine (14),

   ∘ a shaft (13) coupling the turbine and the compressor such that the turbine is able to rotationally drive the compressor,

   ∘ an air inlet (18) of the compressor (15),

   ∘ an air outlet (19) of the compressor (15) delivering an airflow compressed by the compressor,

   ∘ an air inlet (16) of the turbine (14) arranged to receive a compressed airflow from the compressor (15),

   ∘ an air outlet (17) of the turbine (14) delivering an expanded cold airflow,

   - at least one exchanger (20, 23, 24, 32) interposed between the air outlet of the compressor of at least one turbocompressor and the air inlet of the turbine of at least one turbocompressor,

   characterised in that:

   - at least one turbocompressor (11) of at least one air cycle device comprises an electric motor (12) coupled to the compressor (15) so as to be able to deliver mechanical power to the compressor,

   - the air inlet (18) of the compressor (15) of at least one turbocompressor of at least one air cycle device is arranged to receive air at a pressure greater than or equal to atmospheric pressure,

   - each turbocompressor (11) of each air cycle device is associated with a set of controlled valves (40, 45, 49, 50, 55) and conduits, adapted to be able to be controlled in one operating mode selected at least from:

   ∘ a heat pump heating mode in which:

   ▪ the air inlet (18) of the compressor (15) is arranged to receive an expanded airflow from the turbine (14) via at least one heat exchanger, named intermediate heating exchanger (20), adapted to heat the expanded air delivered by the turbine (14) in contact with at least one air stream selected from an external air stream, a foul air stream to be vented out of the cabin, and mixtures thereof,

   ▪ the compressed and heated air delivered to the outlet (19) of the compressor (15) of the turbocompressor passes through a first circuit of a heat exchanger, named cabin heat exchanger, adapted to heat an airflow for supply to the cabin (10) of the vehicle passing through a second circuit of the cabin heat exchanger, an outlet of the first circuit of the cabin heat exchanger being connected to the air inlet (16) of the turbine,

   ∘ a cooling mode in which:

   ▪ the air inlet (18) of the compressor (15) is arranged to receive air external to the vehicle,

   ▪ the compressed air outlet (19) of the compressor (15) is connected to at least one heat exchanger, named intermediate exchanger (20), delivering a compressed air stream cooled by at least one air stream selected from an external air stream, a foul air stream to be vented out of the cabin, and mixtures thereof.
10. Vehicle according to claim 9, characterised in that the turbine of each turbocompressor (11) is arranged to deliver an expanded airflow at a pressure greater than or equal to atmospheric pressure.
11. Vehicle according to any one of claims 9 or 10, characterised in that each air cycle device comprises a set of controlled valves (40, 45, 49, 50, 55) and conduits, and in that it comprises at least one control unit (30) adapted to be able to control each air cycle device in an operating mode selected from:

    - a heating mode in which compressed and heated air delivered to the outlet (19) of the compressor (15) of the turbocompressor (11) passes through at least one first circuit of a heat exchanger adapted to heat an airflow for supply to the cabin (10) of the vehicle,

    - a cooling mode in which:

    ∘ the air inlet (18) of the compressor (15) is arranged to receive air external to the vehicle,

    ∘ the compressed air outlet (19) of the compressor is connected to at least one heat exchanger, named intermediate cooling exchanger (20), delivering a compressed air stream cooled by at least one airstream selected from an external air stream, a foul air stream to be vented out of the cabin, and mixtures thereof.
12. Vehicle according to one of claims 9 to 11, characterised in that it comprises a control unit (30) adapted to control the rotational speed of the electric motor (12) of each turbocompressor (11) based on a set thermal power to be delivered to the cabin (10) of the vehicle.
13. Vehicle according to one of claims 9 to 12, characterised in that said set of controlled valves (40, 45, 49, 50, 55) and conduits is adapted to be able to be likewise controlled in an operating mode selected from a heating mode in which:

    - a foul air stream to be vented out of the cabin is supplied to the inlet of the compressor of the turbocompressor,

    - the compressed and heated air delivered to the outlet (19) of the compressor (15) of the turbocompressor passes through at least one exchanger (20, 23, 24) interposed between the air outlet of the compressor of at least one turbocompressor and the air inlet of the turbine of the turbocompressor,

    - and the air delivered to the outlet of the turbine of the turbocompressor is connected to an outlet orifice (59) to be ejected to the outside.

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